<?PHP // $Id: pix.php,v 1.18.2.1 2007/12/19 17:38:47 skodak Exp $
	  // This function fetches math. images from the data directory
	  // If not, it obtains the corresponding TeX expression from the cache_tex db table
	  // and uses mimeTeX to create the image file

	$nomoodlecookie = true;	 // Because it interferes with caching

	require_once('../../config.php');

	if (empty($CFG->textfilters)) {
		error ('Filter not enabled!');
	} else {
		$filters = explode(',', $CFG->textfilters);
		if (array_search('filter/algebra', $filters) === FALSE) {
			error ('Filter not enabled!');
		}
	}

	// disable moodle specific debug messages
	disable_debugging();

	require_once($CFG->libdir.'/filelib.php');
	require_once($CFG->dirroot.'/filter/tex/lib.php');

	$cmd	= '';			   // Initialise these variables
	$status = '';

	//error_reporting(E_ALL);

	$relativepath = get_file_argument('pix.php');

	$args = explode('/', trim($relativepath, '/'));

	if (count($args) == 1) {
		$image	= $args[0];
		$pathname = $CFG->dataroot.'/filter/algebra/'.$image;
	} else {
		error('No valid arguments supplied');
	}

	if (!file_exists($pathname)) {
		$md5 = str_replace('.gif','',$image);
		if ($texcache = get_record('cache_filters', 'filter', 'algebra', 'md5key', $md5)) {
			if (!file_exists($CFG->dataroot.'/filter/algebra')) {
				make_upload_directory('filter/algebra');
			}

			$texexp = $texcache->rawtext;
			$texexp = str_replace('&lt;','<',$texexp);
			$texexp = str_replace('&gt;','>',$texexp);
			$texexp = preg_replace('!\r\n?!',' ',$texexp);
			$texexp = '\Large ' . $texexp;
			$cmd = tex_filter_get_cmd($pathname, $texexp);
			system($cmd, $status);
		}
	}

	if (file_exists($pathname)) {
		send_file($pathname, $image);
	} else {
		if (debugging()) {
			echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
			echo "Image not found!<br />";
			echo "Please try the <a href=\"$CFG->wwwroot/filter/algebra/algebradebug.php\">debugging script</a>";
		} else {
			echo "Image not found!<br />";
			echo "Please try the <a href=\"$CFG->wwwroot/filter/algebra/algebradebug.php\">debugging script</a><br />";
			echo "Please turn on debug mode in site configuration to see more info here.";
		}
	}
?>
